propane anealing furnace?

[NorCal Nate]

A guy on my local craigslist has a propane anealing funace for sale. I've been thinking on trying to make a propane forge, but would this work? (125$). what do you guys think? Sorry to sound like I dont have a clue, but ...I dont. Thanks ~Nate

[Ray Rogers]

I don't know what an 'annealing furnace' would be exactly. Maybe that means a forge that doesn't get hot enough to use as a forge. In any case, $125 is more than enough to build a simple forge if you can scrounge some of your parts...

[Doug Lester]

For $125 you should be able to build a forge even without scrounging parts, especially if you stick with a venturi burner. If you go with a blown burner the blower might send you over that mark if you couldn't find a discount electrical supply house that was running a good deal. My concern would be size. It sounds like something way too large to use for general forging and not good enough on heat control for or range of temperature that it will hold for heat treating. Something that an electric heat treating oven will do better. I would leave that furnace for someone who needs it for the intended purpose, annealing steel.

Doug

[NorCal Nate]

I just kind of figured the guy didnt really know what he was talking about, or what he has. It is a small unit. I did send him an email, so if he calls I'll ask alot of questions. 125$ seems reasonable to me if it does what I want it to, but if it just anneals steel then I'll just stick with what I already have.

Thanks Doug and Ray!

[NorCal Nate]

Here is the craigslist link.
http://humboldt.craigslist.org/tls/3076777777.html

The guy said it was only like a foot in diameter. And that it gets steel "red hot", however hot that is.

Im going to lokk at it tomarrow.

He also has a hydraulic press, a monster of a Grizzly grinder, and a coal forge.. I wish I had deeper pockets!

[Ray Rogers]

If that's the Grizzly knife 2x72" belt grinder then I think I'd take that $125 plus whatever else was needed at try to acquire that if he's asking a fair price for it. Probably half the knife makers in the country start with that grinder and we all keep them because they are too useful to let them go. Finding one for sale is rare. They sell for about $550 new I think and, again, that's the 2x72" grinder and not one of the manye other grinders sold by Grizzly ....

[NorCal Nate]

Ray it looked like 2x72 grinder. The only problem is he wants 650$ for it and its 3 phase, and I only have the standard 120/240v single phase here at the homested. He said it was a 4 hp motor, which seems huge to me.

[NorCal Nate]

Here Ray...

http://humboldt.craigslist.org/tls/3075886588.html

[Ray Rogers]

No, that's not the 2x72 ......

[NorCal Nate]

Nope, 3x79

http://www.grizzly.com/products/4-HP...t-Sander/G0489

[NorCal Nate]

We I dished out the $ and picked up the forge/furnace. Its a Johnson #121
for 125$ I think I got a good deal.



NO. 121 AND NO. 143 HEAT TREATING AND FORGE FURNACES (Not pictured)
Popular adaptation of the standard No. 120 and No. 142 Furnaces. Especially suitable for the shop where light forging is done as well as heat treating. Special hard refractory bottom and hearth rests are provided. The hearth plate is used for heat treating; plate is removed for forge work so the parts to be forged can be placed on hearth rests.

I think its gonna suit my needs just fine. The guy threw in 2 10' sections of mill saw blades, two planner blades and some cutting heads for a metal lathe.

[Ray Rogers]

Price wise that's not bad. Those Johnson's are what is often found in high school shops. Better suited to heat treating than forging blades but can be used. Not terribly efficient on fuel. It will do the job for you for a while. If you get seriously into forging you'll probably want a forge with a round interior and easier access.

As for the free steel, it isn't free at all. Since you have never forged you don't know much yet about how to test and work metals. Those planer blades are near impossible for a beginner to forge. The lathe cutters probably not a lot different - and note that I said 'probably'. That's because no one knows for sure what they are made of so no one can tell you how to heat treat anything you might make from them and, at this point, you don't know how to figure that out for yourself. The saw blades might be OK if we are willing to assume that the seller actually had some idea of what they really are made from.

The safest and cheapest thing you can do is put all that steel aside and buy some blade steel like 1080 or 1084. It doesn't cost much and you'll get the money back 10 times over in saved propane and grinding belts/disks/wheels/time that would have been used trying to figure out how to make a real knife from mystery metal ...

[NorCal Nate]

Ray, price wise I think I hit a homerun. The Johnson website lists the model #121 at $5,900. As far as fuel goes the spec sheet says it uses 90,000 BTU/hr, so I can get about 4 hours out of a 5 gal. propane tank, Not ideal but I'll work with it. And I agree with you on the "free" steel", true I have no idea what kind of steel it is, but I still might play with it. And I have forged out a few blades on my wood burner "forge", a couple Nicholson files and some coil spring. It's true im new at this and cant be totally sure on my heat treating and forging technique, but thats what learning is all about.

[Ray Rogers]

I'm only guessing here but I don't think it's likely that you'll run that forge for 4 hours on a 5 gal tank. There might be enough fuel for that to work but generally what happens (and with much smaller forges than that one) is that the little propane tank freezes over because the gas is being expelled so fast. That causes the pressure to drop rapidly and soon you don't have enough to run the forge at high temp even though you have plenty of fuel left in the tank. Sitting the tank in a tub of water sometimes helps you get a bit more out of the tank but the real solution is a much bigger tank - at least 100 pounder.

Those planer blades are probably D2. There are few steels harder to forge by hand than D2. D2 is also extremely demanding on forging temperature control, not to mention that you'll never get it heat treated properly without an electric oven. Yes, I know there are guys who think they do it but then they believed Rambo did it in that last movie too ...

[NorCal Nate]

Ray, I'd didnt even consider the tank freezing up.
I still need to get the controls wired up to the forge anywho.
I guess theres alot of variables I didnt consider.

Thanks for your insight! ~Nate